Problem: $ { {-5} \times \left[\begin{array}{rrr}{-1} & {2} & {0} \\ {-1} & {-1} & {-2}\end{array}\right] = {?} } $
Explanation: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-5}\times{-1} & {-5}\times{2} & {-5}\times{0} \\ {-5}\times{-1} & {-5}\times{-1} & {-5}\times{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{5} & {-10} & {0} \\ {5} & {5} & {10}\end{array}\right]}$